Just a thought - if the opamps will be kept in place and continue to function then adding tube output buffer (you do not want to increase audio signal output voltage of the opamps do you?) will just give you the "opamp sound via tube buffer". Also you will be stuffing a tube preamp into the cd player box which makes it unusable for your other sources and also generates unnecessary heat inside the player.
So in case opamps would be still in the signal path I would focus on a tube preamp in external housing with input selector.
There is also a route of using passive I/V conversion and tube output stage - there is more than one thread about it in the digital source section. I have not done it myself so I cannot comment on the details.
The fact that it can be done does not always mean it should be done 😉
So in case opamps would be still in the signal path I would focus on a tube preamp in external housing with input selector.
There is also a route of using passive I/V conversion and tube output stage - there is more than one thread about it in the digital source section. I have not done it myself so I cannot comment on the details.
The fact that it can be done does not always mean it should be done 😉
Thanks my friend from Estonia
You've hit the nail on the head squarely..
Poor mooly has been trying to tame me and take off the lense caps😉
Op amps in. My idea is to enhance the character or Taylor the cd-40 and get the satisfaction of doing it and not Change it out of all recognition. I was looking at ventilation but thats a really good idea using it as a buffer in a separate case with its own power and transformer etc.
Thanks
You've hit the nail on the head squarely..
Poor mooly has been trying to tame me and take off the lense caps😉
Op amps in. My idea is to enhance the character or Taylor the cd-40 and get the satisfaction of doing it and not Change it out of all recognition. I was looking at ventilation but thats a really good idea using it as a buffer in a separate case with its own power and transformer etc.
Thanks
Another approach could be Lampizator´s way of dealing with the TDA1541. Everything after the 1541 is cut away.
I/V is done with 2 x 91-100ohm to ground. Signal straight to 2 pieces of 6N2P-EV with additional PSU. Have tried on a couple of
players, and it sounds very very good,
Google "Lampizator + TDA1541", and you´ll find everything, you need 😉
Or look here: http://www.lampizator.eu/lampizator/references/MARANTZ 40/marantz CD40 lampizator.html
Schematic here: http://www.lampizator.eu/lampizator/TDA1541 corner/schematics 003.jpg
I/V is done with 2 x 91-100ohm to ground. Signal straight to 2 pieces of 6N2P-EV with additional PSU. Have tried on a couple of
players, and it sounds very very good,
Google "Lampizator + TDA1541", and you´ll find everything, you need 😉
Or look here: http://www.lampizator.eu/lampizator/references/MARANTZ 40/marantz CD40 lampizator.html
Schematic here: http://www.lampizator.eu/lampizator/TDA1541 corner/schematics 003.jpg
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Thanks boydk😏
Appreciate advice very much. Ill study this approach and get some knowledge first. Fortunately there is a stack of old tda players under my bed waiting...
It's not a high voltage kit I'm assembling as new to it but it requires 2x 18vac so I'm not sure how good it will turn out? How hot it will run?
Madis64 had a very valid point about not putting inside player due to heat build up. You can pick up old spare repair tuners( marantz ) cheap for example and some have lots of ventilation and all right width. Just add your own face plate? If people do prefer inside cd player would it be cooler with tubes exposed through case?
Ive seen high voltage kits that would look good and be safer in separate box? ( When feel confident, that is)
I would presume the sound quality is a big leap from the low voltage kit?
Appreciate advice very much. Ill study this approach and get some knowledge first. Fortunately there is a stack of old tda players under my bed waiting...
It's not a high voltage kit I'm assembling as new to it but it requires 2x 18vac so I'm not sure how good it will turn out? How hot it will run?
Madis64 had a very valid point about not putting inside player due to heat build up. You can pick up old spare repair tuners( marantz ) cheap for example and some have lots of ventilation and all right width. Just add your own face plate? If people do prefer inside cd player would it be cooler with tubes exposed through case?
Ive seen high voltage kits that would look good and be safer in separate box? ( When feel confident, that is)
I would presume the sound quality is a big leap from the low voltage kit?
Dear all,
Just wanted to post update on project and perhaps useful to other members I hope...
I've cut the plastic carcus front to back leaving just the PCB side, mounted it inside old marantz amp case to left side and added metal shield strengthener to right of PCB plus cover for CDM unit and various mounting plates for tubes and power supplies using the lid and sheet metal working to allow tubes to appear out of top of amp cover. This provide weight/ strength and excellent ventilation. It takes very careful measuring as the main and filament PSU's are mounted below the tube PCB under the plate and miraculously clear the main PCB components underneath?!!( Luck?)
It runs at 28v with 12v DC for tubes it doesn't run hot when tested after assembly but haven't hooked up to cd-40 yet. The two transformers are in the far right metal compartment with mains filter and soft start via ic13 socket now.
Initially I am going to purely have it as a buffer but I'm very interested about suggestions about going straight from TDA and looked extensively on lampizator sight.
Just to clarify:
You take out from pins 6 and 25 with 90-100 ohm resistors across to grounds and then direct to audio in on tube PCB?
Also the £20 tube kit running at 18v with large heatsink all in one despite being tightly packed so decided to take main 4 PSU caps off board and replace with mundorf AG replacing 4x .1uf caps with mundorf zn and cheapest jantzen crosscaps already had but will be experimenting further with high grade oil caps mounted separately again. It was already assembled(unfortunately) and the supplied caps were more than adequate as matched sound quality described.
Forgot to say used this in marantz pm-34 amp with other improvements in the end as more space in there.
Basically, it does everything it says on the tin and more and been running faultlessly for 2 weeks now so highly recommend if you prefer lower voltage and compact.
Just wanted to post update on project and perhaps useful to other members I hope...
I've cut the plastic carcus front to back leaving just the PCB side, mounted it inside old marantz amp case to left side and added metal shield strengthener to right of PCB plus cover for CDM unit and various mounting plates for tubes and power supplies using the lid and sheet metal working to allow tubes to appear out of top of amp cover. This provide weight/ strength and excellent ventilation. It takes very careful measuring as the main and filament PSU's are mounted below the tube PCB under the plate and miraculously clear the main PCB components underneath?!!( Luck?)
It runs at 28v with 12v DC for tubes it doesn't run hot when tested after assembly but haven't hooked up to cd-40 yet. The two transformers are in the far right metal compartment with mains filter and soft start via ic13 socket now.
Initially I am going to purely have it as a buffer but I'm very interested about suggestions about going straight from TDA and looked extensively on lampizator sight.
Just to clarify:
You take out from pins 6 and 25 with 90-100 ohm resistors across to grounds and then direct to audio in on tube PCB?
Also the £20 tube kit running at 18v with large heatsink all in one despite being tightly packed so decided to take main 4 PSU caps off board and replace with mundorf AG replacing 4x .1uf caps with mundorf zn and cheapest jantzen crosscaps already had but will be experimenting further with high grade oil caps mounted separately again. It was already assembled(unfortunately) and the supplied caps were more than adequate as matched sound quality described.
Forgot to say used this in marantz pm-34 amp with other improvements in the end as more space in there.
Basically, it does everything it says on the tin and more and been running faultlessly for 2 weeks now so highly recommend if you prefer lower voltage and compact.